The present invention relates to an arrangement in a drain system, said drain system having a first system section located in a building and adapted to receive drain media from one or a plurality of units as well as a second system section having a main drain conduit in common to a plurality of buildings provided with a first system section and adapted to conduct drain media to one or a plurality of devices for taking care thereof, as well as a method.
Drain media is preferably constituted by drain water, in which said units may be toilets, draining gutters, sinks, wash-hand basins, dishwashers, washing machines and the like, but any other type of drain media is also comprised, and it would for example be possible to transport organic domestic wastes ground into a finally divided form in such a drain system.
However, arrangements and methods of this type already known only transport drain water from the buildings, and a main disadvantage of this prior art is that it is necessary to think far ahead into the future when planning a settlement and try to predict each conceivable expansion of the settlement so that future settlement or buildings may be connected to the same drain system, i.e., to the same main drain conduit. The reason for this is that all the drain water in such arrangements already known has to flow in one direction in the main drain conduit and deeper and deeper into the ground should not the ground profile be inclined in the direction of the main drain conduit. Thus, it is not possible to connect new buildings located on a comparatively low level with respect to other buildings connected to the drain system at a later stage, would not this have been planned from the beginning by digging and locating the main drain conduit sufficiently deep for enabling flowing of drain water from the new settlement to the main drain conduit. Besides the disadvantage that separate drain systems may be necessary for additional settlements, the result of said planning for the future desired is that the entire drain system will be strongly over-dimensioned until the erection of buildings has been xe2x80x9cfinishedxe2x80x9d, which may well take tens of years. This means of course a bad utilizing of the investment in the drain system.
Another disadvantage is, as indicated above, that it will be necessary to put the main drain conduit comparatively deep into the ground at certain locations so as to be able to utilize the gravitation in the way desired, which results in very high costs for digging to put the conduits down and also in later problems with tubing fractures and ground water influence as a consequence of the deep localization of the conduits.
The object of the present invention is to provide an arrangement and a method of the type defined in the introduction, through which the disadvantages mentioned above of such arrangements and methods already known are reduced to a large extent.
This object is according to the invention obtained by designing the main drain conduit of an arrangement of the type defined in the introduction as a closed ring conduit, pump members are arranged to pump drain media emanating from said first system section to and into the ring conduit for transport therein through pumping action, said devices are connected to the ring conduit through a branch each, and valve members are arranged in each connection to the ring conduit and optionally controllable so as to either open so as to allow pumping of drain media into the ring conduit in the case of a feed connection and so as to allow drainage of drain media from the ring conduit in the case of a device connection or close so as to not allow the drain media there to flow into or out of the ring conduit, as well as a method.
By designing the main drain conduit as a closed ring conduit and carrying out the transport of drain media therein through pumping action, the drain media may move in any direction in the main drain conduit. Thus, no height of fall is required along the main drain conduit between the places where drain media is intended to enter into the main drain conduit and the places in which it goes out thereof to said devices, such as purifying plants, but the places last mentioned may even be located on a higher level than those first mentioned. This means in its turn that the ring conduit may be put at a desired depth under the ground surface, for example in the order of 0.5 m, everywhere, so that the tubings may be put into the ground to a low cost. It will of course be considerably less costly than before to dig and reveal the tubings, would this against the expectations be necessary at any time in the future. It is in this way also possible to avoid problems of influence of ground water on the tubing and the environment thereof. Furthermore, it will be very easy to connect new buildings or settlements at a later stage to the main drain conduit, since there is no requirement that the conduits emanating therefrom and leading to the ring conduit have a height of fall with respect to the ring conduit. Another advantage of producing transport of drain media through pumping is that the dimensions of the tubings of the ring conduit may be made considerably smaller than the conventional main drain conduits, since filled conduits are utilized, which of course also results in a saving of costs with respect to the cost for the tubings and for digging and putting them into the ground.
According to a preferred embodiment of the invention said first system section has at least one container for collecting drain media received from said units so as to enable pumping of drain media out from the respective container to the main drain conduit through the pump members at time intervals. It will in this way be possible to utilize the volume of the main drain conduit to an optimum and let for example a certain group, such as a block, of buildings pump out water collected in said container during a certain period of time, for example one day or half a day, during a predetermined period of time into the main drain conduit, such as for example during three hours of the day, while the main drain conduit may be reserved for other groups of buildings during other parts of the day.
According to another preferred embodiment of the invention, which constitutes a further development of the preceding one, pump members are connected to different feed connections to the main drain conduit from different buildings or groups of buildings controllable to pump out drain media into the ring conduit during different periods of time of the day. By such a so called sequence pumping peaks of load on the ring conduit, such as in the morning and in the evening, are avoided and the ring conduit has not to be dimensioned for such peaks, but it may be given a comparatively small dimension by utilizing thereof to an optimum by distributing the load over different periods of time of the day.
According to another preferred embodiment of the invention the arrangement has at least one collecting conduit for drain media in common to a group of buildings and the first system section there of for a connection of the building of the group of buildings in common to the ring conduit, and the conduit is formed by a closed sub-ring conduit having a branch leading to the main drain conduit. Drain water from the different buildings of one or a plurality of blocks may by such a sub-ring conduit be efficiently absorbed.
According to another preferred embodiment of the invention the different buildings in said group of buildings have conduit connections to a place in common located on a low level for transport of drain media to said place through the influence of the gravitation, and a pump member in common is arranged in this place to pump drain media out through said feed conduit in question to the ring conduit. The number of pump members required for bringing drain media out into and transport it in the ring conduit may by this be considerably reduced. It may also be an advantage that traditional drain conduits with self-fall already there may be used for conducting drain media from the different buildings.
According to another preferred embodiment of the invention said first system section is divided into at least two parts, namely a first part adapted to receive drain media of a first type from one or a plurality of first units and a second part adapted to receive drain media of a second, different type from one or a plurality of second units, and said pump members are adapted to produce a supply of drain media of one type at the time to the ring conduit. By separating different types of drain media in this way, such as for example drain water of different degree of contamination, and maintain this separation by supplying drain media of one type at the time to the ring conduit drain media of a certain type may be controlled to a quite particular of these devices for taking care of and utilizing the drain media in question to an optimum.
According to another preferred embodiment of the invention said first system section is divided into at least two parts, namely a first part adapted to receive drain media of a first type from one or a plurality of first units and a second part adapted to receive drain media of a second, different type from one or a plurality of second units, and the respective feed connection to the ring conduit from the respective building or building group has at least two parallel conduits, one for drain media of each said type, and the ring conduit has at least two conduits extending in parallel for receiving and transporting drain media of different types. It will be possible by such a design to carry out the separation desired of drain media of the buildings and maintain this all the way to the different devices, but nevertheless transport drain media of different types simultaneously completely independent of each other. Another advantage of this embodiment is that one and the same conduit may be used for drain media of different types and by that no harmful intermixing of components of a drain media at another stage, maybe in some quite particular later use of the drain media, may take place.
According to a preferred embodiment of the invention, which constitutes a further development of the two embodiments last mentioned, said first part is adapted to receive first drain water contaminated to a comparatively high degree and the second part is adapted to receive second drain water normally contaminated to a lower degree. It may then be a question of drain water emanating from toilets as the first drain water, i.e. so called black water, and from sinks, wash-hand basins, draining gutters and the like, so called blue or green water, as other drain waters. These different types of drain water may be used in quite different ways, in which for example black water is suited as fertilizing means and as a material for production of biological gases, while the blue-green water could be used for watering purposes, be brought through a thick ground layer of sand, gravel or another land-filling material for giving large possibilities to mechanical as well as biological purifying of contamination fractions not desired and present in water delivered or just simple led out into a watercourse, since this is considered to be most acceptable from the environmental point of view by a slow drainage through this ground layer.
According to another preferred embodiment of the invention the arrangement has a conduit for connecting a watercourse to the ring conduit as well as a pump member arranged in this connection conduit and adapted to pump water from the water course out into the ring conduit for a purpose of fire fighting, and the ring conduit has one or a plurality of water drainage members for utilizing water pumped from the watercourse for the purpose of fire fighting. A ring conduit may in this way be utilized for ensuring that different blocks of buildings located there along may receive nearly an unlimited amount of water for fire fighting purposes when this is required.
According to another preferred embodiment of the invention the ring conduit has at least one ejector pump for influencing the drain media to flow in a certain direction in the ring conduit. By arranging such a pump drain media may flow in the conduit also when the pump is switched off, at the same time as it will be possible to influence drain media to flow in a certain direction so as to maybe get a shorter way to go to a determined device mentioned.
According to another preferred embodiment of the invention the tubing/tubings of the ring conduit has a diameter below 100 mm. Calculations have even shown that it is possible to manage with tubings having a diameter below 75 mm, more exactly in the order of 50 mm for a ring conduit running and receiving water from city settlement in the form of houses having several floors. Such thin tubings are much easier to dig into the ground than the main drain conduits of drain systems known until today being giant-like with respect thereto.
The advantages of the different embodiments of the method according to the invention appear from the discussion above of different embodiments of the arrangement according to the invention.
Further advantages as well as advantages features of the invention appear from the following description.